I was in a night class during my second year highschool at Negros Occidental Highschool (NOHS) and Biology is my last subject. I often feel sleepy but our teacher Mr. Barro used to crack jokes and it help me to stay awake until the class ends. Though it was not the first time for me to hear the word DNA, I know that after attending his class the word DNA was never blotted in my mind. But the sad truth is I really don’t pay attention to what was DNA was all about. I know that it stands for DeoxyriboNucleic Acid and it is the genetic material of a cell but I have no interest to learn about its implications. Until lately at UPOU, the first activity was given to us in Natsci 3 asking, “if being a mutant, what would my power be?” it was a mere activity that challenged my little knowledge to study and becoming interested in studying DNA.
Hearing the word Biotechnology makes me think of the traditional biotechnology which is the process of using organisms like in brewing which yeast makes alcohol. Thanks to this subject, it opened my eyes on how biotechnology can be a key element to fight against the hunger, malnutrition and many problems of the world. Like for example the developed “golden rice,” enriched with beta carotene that could help combat vitamin-A deficiency is one of the many contributions of biotechnology in humanity.
As DNA is the carrier of genetic information, genetic engineering initially meant as the artificial manipulation, modification, and recombination of DNA or other nucleic acid molecules in order to modify an organism or population of organisms. I know that this field is not an easy one but history would tell us the breakthrough when a cancer researcher Renato Dulbecco of the Salk Institute in La Jolla, California, began a crusade. A decade earlier, he had won a Nobel Prize for his work on viruses that cause cancer by disrupting genes. He had come to believe that most, if not all, cancers traced back to genetic abnormalities—either inherited or trigged by direct damage such as that caused by viruses, radiation, or toxic chemicals. What cancer research needed, Dulbecco argued, was a complete map of the human genome—the entire nucleotide sequence of the then-estimated 50,000 human genes. Not only would such a map revolutionize cancer research, it could also speed research on treating tens of thousands of other diseases caused wholly or in part by gene defects.
At first, Dulbecco’s idea seemed ludicrous. Geneticists estimated there might be more than 3 billion nucleotides, the biochemical “letters” in the human genome. In addition to ferreting out tens of thousands of working genes, researchers would also have to sort through vast stretches of nonsense, or “junk,” DNA.
Many of the methods of genetic analysis have proved extremely useful in the related field of genetic engineering—the deliberate transformation of one organism using genes from another.
In the early 1970s, researchers found that bacteria and viruses would pick up these genetic fragments, regardless of whether the DNA came from another microbe, plant, or animal. The resulting transgenetic bacteria and viruses were the first products of genetic engineering.
The challenge of genetic engineers was to control the process—that is, to cut out the specific gene from one organism and then induce a microbe to pick up that gene and either use it or insert it into another organism. The first useful product of genetic engineering arrived in 1982 in the form of transgenic bacteria carrying the human gene for the hormone insulin. In effect, the bacteria had been transformed into living insulin factories. Other useful transgenic bacteria followed, many of them also producing therapeutic hormones.
I could say that my knowledge in DNA is limited but I am willing to gather and learn more facts about DNA just to be involved in a discussion re DNA.
The Birth of Dolly
- Embryologist Ian Wilmut removed a cell from the udder of a 6-year-old Finn Dorset ewe. He placed the cell in a nutrient-deprived culture, causing the active genes to switch off, and ensuring that the cell’s DNA would keep working after the transplant.
- An unfertilized egg cell was removed from a second sheep—a Scottish blackface ewe. The egg’s nucleus and DNA were extracted with a needle, but the cellular equipment necessary to produce embryos was left intact.
- The egg and udder cells were placed next to each other and given a jolt of electricity, causing them to fuse. A second jolt prompted cell division forming an embryo.
- After six days, the embryo was implanted in the womb of a third (Scottish blackface) ewe. Five months later, in July 1996, a Finn Dorset lamb named Dolly was born.
Although most people consider cloning—the creation of an exact genetic copy of an organism—as another form of genetic engineering, cloning does, in fact, happen naturally in nature. Many plants and most microbes can reproduce by cloning—that is, by simply passing on an exact copy of their genes without sexual reproduction. Identical twins are examples of clones that develop from the same fertilized egg.
By contrast, cloning that is associated with genetic manipulation involves creating a new organism from a single cell taken from a particular “parent” organism. It does not involve tinkering at the level of individual genes. Rather, biologists have discovered some ways to trick a mature cell into reverting to an earlier stage of its development. In essence, the scientist tells the cell to reactivate the genes responsible for creating a new organism from scratch. Under normal circumstances, these genes remain active only during embryonic development, when a newly fertilized egg begins dividing to produce the many different types of cells needed to create a “baby” organism.
-The New Book of Popular Science (Grolier International, INC.)
-MLA Style: “genetic engineering.” Encyclopædia Britannica. Encyclopaedia Britannica Ultimate Reference Suite. Chicago: Encyclopædia Britannica, 2010.